The present invention relates to a piston type bailer for producing bales of agricultural material.
More particularly, it relates to such a piston type bailer which has a bailing chamber, a pressing piston which reciprocates in the bailing chamber under the action of a crank drive, a supply channel which opens into the pressing channel, and a material feeding element which is associated with the supply channel and is also movable by a crank drive. The movement path of the element is changeable by means of an auxiliary drive which extends from the crank drive of the pressing piston. The feeding element is rotatably supported on a crank pin and is connected with its end opposite to its tips, with an end of a link rod whose other ends are mounted on a position-changeable support.
Piston type bailer of the above-mentioned general type are known in the art. One of such piston type bailer is disclosed, for example, in the European Patent No. 0120780. In the piston type bailer disclosed in this reference, two portions of agricultural material are supplied one after the other by the feeding element to the inlet opening of the bailing chamber closed by the pressing piston. During the third transporting stroke of the feeding element, a third portion is supplied and together with both portions located in front of the filling opening, displaced into the bailing chamber after release of the filling opening. In this manner the whole free chamber produced during the return stroke of the pressing piston is completely filled. The disadvantage of such a bailer is that the auxiliary drive required for changing the movement path of the feeding element is composed of a wheel transmission which is periodically turnable on an axle. First of all, the manufacture of such wheel transmission is very expensive, since for insuring its correct operation even in difficult conditions in the agricultural environment, care always must be taken to prevent deposition of particles in the wheels. On the other hand, damages which take place over certain time and cannot be excluded require the exchange of the whole wheel transmission.